Bucket-fastening means for turbines.



R. H. RICE.

Patented Dec. 4, 1917.

Fig. 2.

gan rrrcn Rieman ron, or LY N, MAssAoHns rTs, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION or new YORK.

BUCKET-FASTENING MEANS roe TURBINES.

1 To all whom z'tmay, concern v i Be itknown thatI, RICHARD H. Rios, a citizen of the United States, residing at Lynn, in the county of Essex, State of following is a specification.

The present invention relates to bucket wheels for elastic fluid turbines and has for its objectto, provide animproved structure I for attaching-the bucketbas'es to the wheel rim.

For aconsideration of what I believe to be novel and my invention, attention is di:;

1 one embodiment of my invention, Figure 1:

rected to the accompanying specification and the claims appended thereto.

In-the drawing wherein I have illustrated is a radial sectional view of half of a turbme bucket wheel; Fig. 2 1S asectlonal view -on alarger scale thanFig. .1 of my imaim enabled to make a very substantial reduction in the weight of the bucket wheels ibyreason of thefact that the stresses in the proved bucket fastening means, and Fig. 3

is a fragmentary side View of a portion of;-.

a'bucket wheel.

Referring to the drawing, 5 indicates a short section of a turbine shaft, and 6 indicates the web member of a bucket wheel which is mounted thereon in any approved manner. The rim of the web member is provided on opposite sides with a plurality of annular circumferential grooves or channels 7 which form necks 8 and ridges 8 having substantially straight inner faces 9. In the present instance I have shown two ridges on each side, this being the minimum number I may employ, but it will be understood that I might, within the scope of my inven tion, use more than two. 10 indicates locking rings which are shown as formed integral with the web adjacent its periphery. 11 indicates the buckets having their bases 12 provided with undercut slots or grooves 13 forming ridges 14 which engage in the grooves 7, the ridges 14 having straight flat faces 15 which engage with faces 9. The inner portions of the bases project down within the confines of the locking rings 10. These locking rings, which may be of any suitable contour, prevent the two portions of the bucket bases, which are on opposite sides of the wheel rim, from spreading under the tensile stresses set up by centrifugal force.

According to my invention the inter-em Patented Dec. 4, 1911.7.

.1 Application filed November 26, 1915. Serial No. 63,441.

.gagin'g parts of the wheel 'rim and bucket bases are so constructed that there will be the same stress per square inch 1n each of the necks 8, and the same crushing pres sure on the faces 9 of each of the ridges 8% yThis means that in the arrangement illustrated the inner neck 8 must be of greater fwidth than the outerneck 8 and, as will be seenfrom Fig. 2, leads to a structure wherein the wheel rim tapers from the point where the locking rings 10 are located to the periphery. At the same time the base of eachof the buckets is so constructed that the same load. per square inch is earned by 1t throughits length. ThIS means, in

the. structure illustrated, that the two parts -of the bucket base taper in the opposite diit rection from that of the wheel rim; that is,

the inner portion of them is not so thick as the outer portlon. This gives the greater strength in each instance at the points where it is most needed. Bythis arrangement I buckets and wheel rim are so distributed that they are carried by the minimum amount of material. Both the bucket bases and the wheel rim may be made considerably lighter and of lesser axial dimensions. This results, not only in a reduction in the cost of the wheel structures themselves, but also in the remainder of the turbine, since the length of the turbine is decreased owing to the decreased dimensions of the wheels, and the weights to be carried on the shaft and in the bearings are also considerably decreased.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

WVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. A bucket wheel for an elastic fluid turbine, comprising a web member having a plurality of circumferential channels on opposite sides of its rim forming ridges, said rim tapering from the innermost channel to the periphery, and buckets having their bases formed with undercut slots which fit over the rim, with the undercut portion of theslots receiving said ridges, the two por- V stresses per square inch in therim and bases.

2. A bucket wheel for an elastic fluid turbine comprising a web member having a plurality of circumferential channels on opposite sides of its rim forming ridges, and buckets having their bases formed with undercut slots which fit over the rim with the undercut portion of the slots receiving said ridges, said rim tapering radially from the innermost channel to the periphery, and the portions of the bucket bases on opposite sides of the rim tapering inthe opposite direction, so as to provide substantially equal stresses per square inch at all points in said rim and bucket bases.

3. A bucket wheel for an elastic fluid turbine comprising a web member having a plurality of circumferential channels on opposite sides of its rim forming ridges, buckets having their bases formed with undercut slots which fit over the rim with the undercut portion of the slots receiving said ridges, and locking means which engage the radially inner portion of the side surfaces of the bucket bases, said rim tapering radially from the innermost channel to the periphcry, and the portions of the bucket bases on opposite sides of the rim tapering in the Copies of this patent may be obtained for 4. A bucket wheel for an elastic fluid turbine comprising a web member having two circumferential channels on each side of its rim forming two ridges, locking rings formed integral with the rim, and buckets having their bases provided with undercut slots which fit over the rim; with the undercut portion of the slots receiving said ridges and their radially inner portions engaging the locking ring, said rim tapering radially from the innermost channel to the periphery, and the portions of the bucket bases on opposite sides of the rim tapering in the opposite direction, so as to provide substantially equal stresses per square inch at all points in said rim and bucket bases.

5. A bucket wheel for an elastic fluid turbine comprising a web member having a tapered rim, circumferential channels formed on opposite sides of the rim providing ridges, buckets having theirbases formed with undercut slots, the side walls of said slots tapering in the opposite direction to that of the rim and fitting over the rim with the ridges in engagement with the slots, and circumferential locking rings formed integral with the web which engage the bucket bases to preventthem from spreading.

In witness whereof, I have hereunto set my hand this 22nd day of November, 1915.

RICHARD H. RICE.

five cents eachQby addressing the Commissioner p1 Patents.

Washingtoml). G. l v 

